Changes in microorganism, enzyme, aroma of hami melon (Cucumis melo L.) juice treated with dense phase carbon dioxide and stored at 4 °C

The effects of dense phase carbon dioxide (DP-CO₂) treatment of 8, 15, 22, 30 and 35 MPa for 5 min, 15 min, 30 min, 45 min, 60 min at 35 °C, 45 °C, 55 °C, 65 °C on microorganism, enzyme, and aroma compounds in hami melon juice during storage at 4 °C for 4-weeks were investigated. Meanwhile, the color, browning degree, and Vitamin C were also studied. The DP-CO₂ treatment had significant effects on inactivation of microorganism and enzyme. It was indicated that higher pressure caused more inactivation of microbial total count and enzyme activity. When it reached 35 Mpa, 55 °C, 60 min, the microorganism was totally inactivated. The least residual activity of polyphenol oxidase (PPO), peroxidase (POD), and lipoxygenase (LOX) was 25.26%, 38.46 and 0.02% at 35MP, respectively. The restoration of PPO, POD and LOX residual activity after DP-CO₂ treatment was also observed, which was dependent on the pressure level. The aroma compounds were less affected after being treated with DP-CO₂, and the flavor of the melon juice was close to the fresh juice after storage at 4 °C for 4 weeks and did not produced cook off-odor. The changes of lightness L and browning degree A during storage were well fitted to a first-order kinetic model. The Vitamin C concentration decreased by DP-CO₂ processing, but this loss was lower than of the untreated sample.

Industrial relevance

Hami melon is highly appreciated for its nutritional quality and special flavor. The flesh of melon is heat sensitive, the sensitive nutrients, color and aromatic profile will be spoiled greatly or off-odour when it was produced with high temperature treatment. Dense phase carbon dioxide processing (DP-CO₂) is important to find an innovative food process to inactivate the enzyme and microorganism and protect the nutrient and unique flavor. In this study, the data proved that DP-CO₂ processing is a promising non-thermal alternative pasteurization to preserved fresh-squeezed melon juice.     

Purification, characterization, and gene cloning of sphingomyelinase C from Streptomyces griseocarneus NBRC13471

Sphingomyelinase C (SMC) was purified to homogeneity from the culture supernatant of Streptomyces griseocarneus NBRC13471. The purified enzyme appeared as a single band of 38 kDa by using an electropherogram trace. The molecular mass of the enzyme as determined by MALDI-TOF MS was 32,102 Da, indicating that SMC is monomeric in nature. Under experimental conditions, the highest enzyme activity was found at pH 9.0 and 50–55 °C, and the enzyme was stable from pH 5 to 10 and up to 37 °C. The SMC activity requires Mg²⁺ or Mn²⁺ and the order of potency to enhance the activity was Zn²⁺ ≥ Mn²⁺ > Cu²⁺ ≥ Fe²⁺. Phenylmethylsulfonyl fluoride and EDTA inhibited the enzyme activity, showing that SMC belongs to a group of metalloenzymes and a class of serine hydrolases. The enzyme activity was inhibited by DTT, but not by mercaptoethanol and iodoacetamide. SDS inhibited the enzyme activity; by contrast, Triton X-100 stimulated the activity. The N-terminal and internal amino-acid sequences were determined as H₂N-APAAATPSLK, AREIAAAGFFQGND, and NTVVQETSAP. The gene encoding SMC consisted of 1020 bp encoding a signal peptide of 42 amino acids and a mature protein of 297 amino acids with a calculated molecular mass of 32,125 Da. The conserved region of DNase I-like family enzymes and the amino acid residues that are highly conserved in the active center of other bacterial SMCs were also found in the deduced amino acid sequence of S. griseocarneus SMC.     

Biochemical and thermal characterization of crude exo-polygalacturonase produced by Aspergillus sojae

Crude exo-polygalacturonase enzyme (produced by Aspergillus sojae), significant for industrial processes, was characterized with respect to its biochemical and thermal properties. The optimum pH and temperature for maximum crude exo-polygalacturonase activity were pH 5 and 55 °C, respectively. It retained 60–70% of its activity over a broad pH range and 80% of its initial activity at 65 °C for 1 h. The thermal stability study indicated an inactivation energy of E_d = 152 kJ mol⁻¹. The half lives at 75 and 85 °C were estimated as 3.6 and 1.02 h, respectively. Thermodynamic parameters, ΔH^*, ΔS^* and ΔG^*, were determined as a function of temperature. The kinetic constants K_m and V_max, using polygalacturonic acid as substrate, were determined as 0.424 g l⁻¹ and 80 μmol min⁻¹, respectively. SDS-PAGE profiling revealed three major bands with molecular weights of 36, 53 and 68 kDa. This enzyme can be considered as a potential candidate in various applications of waste treatment, in food, paper and textile industries.     

An enzyme possessing both glutathione-dependent formaldehyde dehydrogenase and S-nitrosoglutathione reductase from Antrodia camphorata

Glutathione-dependent formaldehyde dehydrogenase (GFD or GSH-FDH) plays important roles in formaldehyde detoxification and antioxidation. A gene encoding GFD from Antrodia camphorata was identified based on sequence homology. The deduced amino acid sequence of 378 amino acid residues is conserved among the reported GFDs. To characterise the Ac-GFD, the coding region was subcloned into a vector pET-20b(+) and transformed into Escherichia coli. The recombinant GFD was expressed and purified by Ni²⁺-nitrilotriacetic acid Sepharose. This purified enzyme showed a single band on a 10% SDS–PAGE. The enzyme retained 50% GFD activity after heating at 50 °C for 5 min. The enzyme is bifunctional. In addition to the GFD activity, it also functions as an effective S-nitrosoglutathione reductase (GSNOR) presumably to safeguard against nitrosative stress. The K_m values for S-hydroxymethylglutathione and S-nitrosoglutathione were 1.20 and 0.28 mM, respectively.     

Effect of temperature on the life cycle of Aleuroglyphus ovatus (Acari: Acaridae) at four constant temperatures

The effect of four constant temperatures (20, 24, 28 and 32 °C) on the physiological properties (survival, developmental time, sex ratio, fecundity and longevity of females), and population growth of Aleuroglyphus ovatus was examined in the laboratory at 85% relative humidity. The total developmental time, longevity and oviposition period of A. ovatus shortened as temperature increased. The shortest developmental time (14.70 ± 0.34 days) was obtained at 32 °C. At 20, 24, 28 and 32 °C, mated females laid on average 0.87 ± 0.10, 2.57 ± 0.13, 3.14 ± 0.27 and 1.29 ± 0.16 eggs per day, respectively. Maximum fecundity was recorded at 28 °C with 70.83 ± 10.16 eggs per female. The highest intrinsic rate of increase (r_m) was found to be 0.16 at 28 °C.     

Comparative analysis of acid resistance in Listeria monocytogenes and Salmonella enterica strains before and after exposure to poultry decontaminants. Role of the glutamate decarboxylase (GAD) system

Data on the ability of chemical poultry decontaminants to induce an acid stress response in pathogenic bacteria are lacking. This study was undertaken in order to compare the survival rates in acid broths of Listeria monocytogenes and Salmonella enterica strains, both exposed to and not exposed to decontaminants. The contribution of the glutamate decarboxylase (GAD) acid resistance system to the survival of bacteria in acid media was also examined. Four strains (L. monocytogenes serovar 1/2, L. monocytogenes serovar 4b, S. enterica serotype Typhymurium and S. enterica serotype Enteritidis) were tested before (control) and after exposure to trisodium phosphate, acidified sodium chlorite, citric acid, chlorine dioxide and peroxyacids (strains were repeatedly passed through media containing increasing concentrations of a compound). Stationary-phase cells (10⁸ cfu/ml) were inoculated into tryptic soy broth (TSB) acidified with citric acid (pH 2.7 and 5.0) with or without glutamate (10 mM) added, and incubated at 37 °C for 15 min. Survival percentages (calculated from viable colonies) varied from 2.47 ± 0.67% to 91.93 ± 5.83%. L. monocytogenes cells previously exposed to acid decontaminants (citric acid and peroxyacids) showed, when placed in acid TSB, a higher (P < 0.05) percentage of survival (average 38.80 ± 30.52%) than control and pre-exposed to non-acidic decontaminants strains (22.82 ± 23.80%). Similar (P > 0.05) survival percentages were observed in previously exposed to different decontaminants and control Salmonella strains. The GAD acid resistance system did not apparently play any role in the survival of L. monocytogenes or S. enterica at a low pH. This study demonstrates for the first time that prior exposure to acidic poultry decontaminants increases the percentage of survival of L. monocytogenes exposed to severe acid stress. These results have important implications for the meat industry when considering which decontaminant treatment to adopt.     

Heat-stable proteases from psychrotrophic pseudomonads: secondary structure and heat stability

Circular dichroism (CD) spectral analysis of a purified protease of Pseudomonas fluorescens T16 was carried out at different temperatures to determine the relationship between its secondary structure and its heat-stability. The protease protein was found to be 33% β-structure and 67% random coil. The protein lacked α-helical structure. Unfolding of the enzyme molecule was increased from 25°C, with maximum unfolding at 45°C. The enzyme exhibited maximum inactivation (low temperature inactivation [LTI] phenomenon) at temperatures between 45 and 55°C. At higher temperatures (60–95°C) the protease appears to undergo an additional conformational change to a more ordered stable structure. Metal ions such as Ca²⁺ appeared to be involved in structural stabilization and are required for protection against heat inactivation. The comparisons of amino acid composition, sequence homology, hydrophobicity index and polarities of heat-stable proteases were made to predict their heat-stabilities.     

Effects of photosensitisation and autoxidation on the changes of volatile compounds and headspace oxygen in elaidic trans fatty acid and oleic cis fatty acid

Headspace volatiles and oxygen in elaidic or oleic acids under methylene blue photosensitisation at 60 °C for 60 h were analysed by solid-phase microextraction (SPME)–gas chromatography (GC) with a mass selective detector (MS) and GC with a thermal conductivity detector (TCD), respectively. Headspace oxygen was significantly depleted in photosensitised samples compared to those in the dark (p < 0.05). Oleic acid absorbed more oxygen than elaidic acid for 60 h photosensitisation at 60 °C. Total volatiles from elaidic or oleic acids under photosensitisation increased significantly than those from samples in the dark for 60 h, respectively (p < 0.05). The increasing rates of oxidised volatiles in elaidic acid under photosensitisation were higher than those in oleic acid for 60 h. Peak areas of t-2-undecenal, 1-octanol and 1-heptanol were greatly increased in both elaidic and oleic acids under photosensitisation. Photosensitisation accelerated formation of volatiles in elaidic acid more than in oleic acid while oleic acid absorbed more oxygen than elaidic acid at 60 °C for 60 h.     

Kinetic studies of the thermal inactivation of plasmin in acid or sweet whey

The thermal behaviour of the milk alkaline proteinase, plasmin, was studied in acid and sweet (rennet) whey; indigenous (bovine) plasmin was studied in the former system, but endogenous porcine plasmin was added in the latter, due to the very low levels of residual plasmin. The inactivation of plasmin in both systems followed first-order inactivation kinetics, which was consistent with previous observations of plasmin inactivation in milk and model milk systems. The thermal inactivation of plasmin in acid whey (D_{90 °C}=108±29 min, z=24.5±1.2 °C) was much slower than in the sweet whey system (D_{90 °C}=0.021±0.006 min, z=7.3±0.3 °C). Similarly, denaturation of β-lactoglobulin (β-lg) followed a first-order inactivation profile and this protein was also more heat stable in acid whey (D_{90 °C}=86±76 min, z=13.7±1.5 °C) than sweet whey (D_{90 °C}=0.81±0.29 min, z=9.1±0.5 °C). While it is possible that the increased heat stability of plasmin in acid whey is due to reduced sulphydryl/disulphide interchange reactions between plasmin and β-lg, it also appears that structural changes in the plasmin molecule were a significant contributory effect on the thermal stability of plasmin in this system. Increasing the pH of acid whey decreased the heat stability of plasmin. However, adjusting the pH of sweet whey had little effect on the heat stability of plasmin. Overall, severe heat treatments may be required to ensure inactivation of the enzyme in acid whey, but a balance is required between reducing the activity of plasmin and maintaining the functionality of whey proteins as food ingredients.     

Destruction of acid- and non-adapted Listeria monocytogenes during drying and storage of beef jerky

Presence of Listeria monocytogenes in ready-to-eat meat products is not desired and strictly regulated in the US. Inactivation of acid- and non-adapted L. monocytogenes inoculated on beef slices was studied during drying and storage of jerky formulated with modified marinades. The inoculated (five-strain composite, c. 6·2 log cfu cm⁻²) slices were subjected to marinades (4°C, 24 h) prior to drying (60°C for 10 h) and aerobic storage (25°C for 60 days). The predrying marinade treatments tested were, first, no treatment, control (C); second, traditional marinade (TM); third, double amount of TM modified with 1·2% sodium lactate, 9% acetic acid, and 68% soy sauce containing 5% ethanol (MM); fourth, dipping into 5% acetic acid for 10 min and then applying the TM (AATM); and fifth dipping into 1% Tween 20 for 15 min and then into 5% acetic acid for 10 min followed by the TM (TWTM). Bacterial survivors on beef slices were determined during drying and storage using tryptic soy agar with 0·1% pyruvate (TSAP), and PALCAM agar. Results indicated that drying reduced bacterial populations in the order of pre-drying treatments TWTM (5·9–6·3 log cfucm⁻² in 10 h)≥AATM≥MM>TM≥C (3·8−4·6 log cfucm⁻² in 10 h). No significant (P≥0·05) difference was found in inactivation of acid-adapted and non-adapted inocula within individual treatments. Bacterial populations dropped below the detection limit (−0·4 log cfucm⁻²) as early as 4 h during drying or remained detectable even after 60 days of storage depending on acid-adaptation, predrying treatment, and agar media. These results indicated that acid-adaptation may not increase resistance to microbial hurdles involved in jerky processing and that use of modified marinades may improve the effectiveness of drying in inactivating L. monocytogenes.     

Purification and characterization of dibenzothiophene (DBT) sulfone monooxygenase, an enzyme involved in DBT desulfurization, from Rhodococcus erythropolis D-1

Dibenzothiophene (DBT), a model of organic sulfur compound in petroleum, is microbially desulfurized to 2-hydroxybiphenyl by Rhodococcus erythropolis D-1. Three desulfurization (Dsz) enzymes—DszC, A, and B—and flavin reductase are involved in sulfur-specific DBT desulfurization. In this study, DszA was purified, characterized, and crystallized from R. erythropolis D-1. DszA, DBT sulfone monooxygenase, is the second enzyme in microbial DBT desulfurization metabolism and catalyzes the conversion of DBT sulfone to 2′-hydroxybiphenyl 2-sulfinic acid in the presence of flavin reductase with cleavage of the carbon-sulfur bond in the DBT skeleton. Using anion-exchange column chromatography, the four enzyme fractions responsible for DBT desulfurization were separated, and DszA was then purified to homogeneity. Polygonal crystals of DszA were observed within a week. DszA was found to have a molecular mass of 97 kDa and to consist of two subunits with identical masses of 50 kDa. The N-terminal amino acid sequence of the purified DszA completely coincided with the deduced amino acid sequence for dszA of R. erythropolis IGTS8 except for a methionine residue at the latter N-terminal. The optimal temperature and pH for DszA activity were 35°C and about 7.5. The activity of the enzyme was inhibited by Mn²⁺, Ni²⁺, 2,2′-bipyridine, and 8-quinolinol, suggesting that a metal might be involved in its activity. DszA acted on not only DBT sulfone but also on dibenz[c,e][1,2]oxathiin 6-oxide and dibenz[c,e][1,2]oxathiin 6,6-dioxide. Dihydroxybiphenyl was formed from the latter two substrates.     

Taiwanofungus camphorata nitroreductase: cDNA cloning and biochemical characterisation

Nitroreductases (Nrs) play important roles in redox system via NADPH or NADH as a reductant. A TcNr cDNA encoding a putative Nr was cloned from Taiwanofungus camphorata. A 3-D structural model of the TcNr has been created based on the known structure of BcNr (Bacillus cereus). To characterise the TcNr, the coding region was subcloned into an expression vector and transformed into Escherichia coli. The recombinant His₆-tagged TcNr was purified by Ni affinity chromatography. The purified enzyme showed a single band at molecular mass of approximately 25 kDa on 12% sodium dodecyl sulphate–polyacrylamide gel electrophoresis. The enzyme exhibited Nr activity via ferricyanide assay. The Michaelis constant (K_M) value for ferricyanide was 0.86 mM. The enzyme^’s half-life of deactivation at 45 °C was 12.3 min. The enzyme was most active at pH 6. The enzyme’s preferred substrate is 1-chloro-2, 4-dinitrobenzene.     

Synthesis and partial characterization of octenylsuccinic starch from Phaseolus lunatus

Phaseolus lunatus starch was modified by esterification with octenyl succinic anhydride (OSA) and reaction effect evaluated in terms of chemical composition, gelatinization, pasting and emulsification properties. Succinylation was done using a 2³ factorial design with four replicates of the central treatment. Evaluated factors and levels were OSA concentration (1% and 3%), pH (7 and 9) and reaction time (30 and 60 min). Succinyl group percentage was the response variable. The optimum treatment was a reaction with 3% OSA at pH 7 for 30 min, which produced 0.5083% succinyl groups and 0.0083° of substitution. No significant changes were observed in proximate composition between the native and derivative starches. Apparent amylose level decreased notably from 32.4% to 23.6% due to OSA inclusion. Succinylation decreased starch gelatinization temperature (75.3–64.6 °C), decreased enthalpy (10.7–9.7 J/g), increased viscosity (700–1000 BU), increased emulsifying capacity (0.47–0.53 ml oil/ml sample), and made emulsions more stable over time. Starch modification did not, however, improve stability in heating–cooling processes.     

Byssochlamys nivea inactivation in pineapple juice and nectar using high pressure cycles

The aim of this work was to assess the inactivation of Byssochlamys nivea ascospores in pineapple juice and nectar by combining pressure sequences involving high pressure cycles with relatively mild thermal processing. The effect of 550 and 600 MPa sustained pressures (holding time of 15 min), combinations of sustained pressures and pressure pulses (holding time of 10 s), and pressure cycles (two, three and five cycles of 550 and 600 MPa for 7.5, 5 and 3 min, respectively), at 20, 40, 60, 70, 80 and 90 °C were compared. B. nivea ascospores were inactivated by applying sustained a pressure of 600 MPa at 90 °C for 5 min (juice) and 15 min (nectar), and three and five cycles of pressure at 600 MPa and 80 °C for nectar with holding time of 5 and 3 min, respectively, and in all pressure cycles for juice. In general, pressure cycles were more effective for inactivating B. nivea ascospores than the application of sustained high pressures.     

Effect of controlled gelatinization in excess water on digestibility of waxy maize starch

An aqueous dispersion of waxy maize starch (5%, w/w) was controlled gelatinized by heating at various temperatures for 5 min. The treated samples were analysed using in vitro Englyst assay, light microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier-transform infrared spectroscopy. When heated, SDS and RS levels were decreased inversely with RDS. A high SDS content (>40%) was kept prior to the visible morphological and structural changes (before 60 °C). Swelling factor began to increase slightly at 50–60 °C and continued to maximum value at 80 °C. A large decrease in ΔH, crystallinity, and ratio of 1047/1022 cm⁻¹ attributed to partially dissociation of crystalline clusters and double helices occurred at 65–80 °C. These changes showed that controlled gelatinized starch with slow digestion property occurred in the molecular rearrangement process before granule breakdown and SDS mainly consists of amorphous regions and a small portion of less perfect crystallites.     

Survival kinetics of Ephestia kuehniella eggs during 46–75 °C heat treatment

The effect of heat treatment on the survival of Ephestia kuehniella eggs was examined. Samples of 60 eggs were immersed in hot water at constant temperature in the 46–75 °C range for 5–1200 s. Following heat treatment and cooling, the eggs were stored at 24 ± 1 °C in a growth chamber for 7 days before survival evaluation. Statistical analysis of the data demonstrated that the thermal survival kinetics were best represented by a first-order reaction. The rate constant had an Arrhenius-type dependence over the 54–75 °C temperature range. Kinetic parameters were estimated by non-linear regression. The activation energy (E_a) and rate constant (k_ref) at the reference temperature (T_ref = 64.8 °C), were determined as 102.2 ± 6.2 kJ mol⁻¹ and 0.061 ± 0.003 s⁻¹, respectively, over the 54–75 °C temperature range. A 0.01% survival rate was obtained after 50 s at 75 °C. The data at temperatures below 50 °C were not in accordance with those at higher temperatures. Above this temperature, mortality was likely due to physiological disorders, as noted on a DSC thermogram.     

Storage stability of jackfruit (Artocarpus heterophyllus) powder packaged in aluminium laminated polyethylene and metallized co-extruded biaxially oriented polypropylene during storage

Total colour difference (ΔE), rates of adsorbed moisture and sensory attributes of drum-dried jackfruit powder packaged in aluminium laminated polyethylene (ALP) and metallized co-extruded biaxially oriented polypropylene (BOPP/MCPP) pouches stored at accelerated storage (38 °C, with 50%, 75% and 90% relative humidity (RH)) were determined over 12 weeks period. The changes in total colour followed zero order reaction kinetics. Packaging materials, storage temperature and RH values significantly (p < 0.05) influenced the rates of adsorbed moisture of jackfruit powder. There was a significant (p < 0.05) decrease in the intensities of the fruity odour, taste and increase in the lumpiness of the jackfruit powder stored at 38 °C with 90% RH. The shelf life of jackfruit powder stored at 38 °C and 90% RH was limited by overall acceptability and the intensity of fruity odour, taste and lumpiness at week 8 of storage. Jackfruit powder stored at 28 °C remained stable and acceptable throughout the storage period for all RH values. The powder packaged in ALP significantly (p < 0.05) reduced total colour change, rates of adsorbed moisture, lumpiness intensity of jackfruit powder and was rated higher in terms of overall acceptability over BOPP/MCPP. Results of this study suggested that ALP packaging with storage conditions of 28 °C and RH less than 75% was better suited for keeping jackfruit powder.     

Effect of heat and thermosonication treatments on watercress (Nasturtium officinale) vitamin C degradation kinetics

The use of ultrasound in food processing creates novel and interesting methodologies, which are often complementary to classical techniques. In this work, the effect of heat and the combined treatment heat/ultrasound (thermosonication) on the thermal degradation kinetics of vitamin C in watercress (Nasturtium officinale) was studied in the temperature range of 82.5 to 92.5 °C. First order reaction kinetics adequately described the vitamin C losses during both blanching processes.The activation energies and the reaction rates at 87.5 °C for heat (H) and thermosonication (Ts) treatments were, respectively, E_avitCH = 150.47 ± 42.81 kJ mol^− 1 and E_avitCTs = 136.20 ± 60.97 kJ mol^− 1, and k_{87.5 °CvitCH} = 0.75 ± 0.10 min^− 1 and k_{87.5 °CvitCTs} = 0.58 ± 0.11 min^− 1. No significant differences (P > 0.05) were detected between both treatments. The thermosonication treatment was found to be a better blanching process, since it inactivates watercress peroxidase at less severe blanching conditions and consequently retains vitamin C content at higher levels. The present findings will help to optimise the blanching conditions for the production of a new and healthy frozen product, watercress, with heat and a new blanching process methodology.

Industrial relevance

Thermosonication blanching can be useful since it reduces processing times, and consequently minimizes the adverse effects of heating on watercress quality. This new application will provide good material, in terms of vitamin C, for further processes, and can be an excellent alternative to the traditional heat treatment.     

In vitro evaluation of red and green lettuce (Lactuca sativa) for functional food properties

Lettuce (Lactuca sativa) is an important leafy vegetable consumed fresh or in salad mixes. We have compared the functional food properties of selected commercial red and green lettuce varieties grown under field conditions. Both lettuce cultivars were extracted with water at biological (38 °C) and room temperatures (22 °C) at pH 2. The residues from each extraction were further extracted, sequentially with methanol and ethyl acetate. The extracts were evaluated for their in vitro lipid peroxidation (LPO) and cyclooxygenase enzyme (COX) inhibitory activities. Amongst the extracts tested, all three extracts of red lettuce showed higher LPO and COX-1 and -2 enzyme inhibitory activities than did the green lettuce extracts. Red lettuce contained a single anthocyanin, cyanidin-3-O-(6″-malonyl-β-glucopyranoside) (1), which immediately converted to cyanidin-3-O-(6″-malonyl-β-glucopyranoside methyl ester) (2) and cyanidin-3-O-β-glucopyranoside (3) under laboratory conditions. Anthocyanins 1 and 2 inhibited LPO by 88% and 91.5%, respectively, at 0.25 μM concentration. Also, they inhibited COX-2 enzyme by 78.9% and 84.3% and COX-1 by 64% and 65.8%, respectively, at 5 μM. The chicoric acid (4), amongst other phenolics, such as quercetin glucoside, ferulic and caffeic acids, isolated from both green and red lettuce, showed 85.6%, 45.6% and 94% of LPO, COX-1 and -2 enzyme inhibitions at 50 μM, respectively. This is the first report of the LPO, COX-1 and -2 enzyme inhibitory activities of compounds 1, 2 and 4. The variation of phenolics in the red and green lettuces, and specifically the lack of anthocyanins in green lettuce, might account for the higher biological activity obtained with the red variety in our study.